1. Field
This disclosure relates generally to analog-to-digital converters, and more specifically, to a configurable continuous time sigma delta analog-to-digital converter.
2. Related Art
Two types of sigma delta analog-to-digital (ADC) converters are continuous time sigma delta ADCs and discrete time sigma delta ADCs. One difference between the two converter types is in the type of feedback digital-to-analog (DAC) signal used. A continuous time sigma delta ADC can use an RC, LC, gm-C, or other continuous time filter, while a discrete time sigma delta ADC can use a switched capacitor filter. An accurate clock is more important for a continuous time sigma delta ADC than it is for a discrete time sigma delta ADC. A continuous time sigma delta ADC is more sensitive to clock jitter. Also, a continuous time sigma delta ADC provides better accuracy, inherent anti-aliasing, and higher operating frequency than a discrete time sigma delta ADC. Sometimes a system needs the performance or power advantage of a continuous time sigma delta ADC and other times it does not.